﻿/*
 * FCKeditor - The text editor for Internet - http://www.fckeditor.net
 * Copyright (C) 2003-2009 Frederico Caldeira Knabben
 *
 * == BEGIN LICENSE ==
 *
 * Licensed under the terms of any of the following licenses at your
 * choice:
 *
 *  - GNU General Public License Version 2 or later (the "GPL")
 *    http://www.gnu.org/licenses/gpl.html
 *
 *  - GNU Lesser General Public License Version 2.1 or later (the "LGPL")
 *    http://www.gnu.org/licenses/lgpl.html
 *
 *  - Mozilla Public License Version 1.1 or later (the "MPL")
 *    http://www.mozilla.org/MPL/MPL-1.1.html
 *
 * == END LICENSE ==
 *
 * This class partially implements the W3C DOM Range for browser that don't
 * support the standards (like IE):
 * http://www.w3.org/TR/DOM-Level-2-Traversal-Range/ranges.html
 */

var FCKW3CRange = function( parentDocument )
{
    this._Document = parentDocument ;

    this.startContainer    = null ;
    this.startOffset    = null ;
    this.endContainer    = null ;
    this.endOffset        = null ;
    this.collapsed        = true ;
}

FCKW3CRange.CreateRange = function( parentDocument )
{
    // We could opt to use the Range implementation of the browsers. The problem
    // is that every browser have different bugs on their implementations,
    // mostly related to different interpretations of the W3C specifications.
    // So, for now, let's use our implementation and pray for browsers fixings
    // soon. Otherwise will go crazy on trying to find out workarounds.
    /*
    // Get the browser implementation of the range, if available.
    if ( parentDocument.createRange )
    {
        var range = parentDocument.createRange() ;
        if ( typeof( range.startContainer ) != 'undefined' )
            return range ;
    }
    */
    return new FCKW3CRange( parentDocument ) ;
}

FCKW3CRange.CreateFromRange = function( parentDocument, sourceRange )
{
    var range = FCKW3CRange.CreateRange( parentDocument ) ;
    range.setStart( sourceRange.startContainer, sourceRange.startOffset ) ;
    range.setEnd( sourceRange.endContainer, sourceRange.endOffset ) ;
    return range ;
}

FCKW3CRange.prototype =
{

    _UpdateCollapsed : function()
    {
      this.collapsed = ( this.startContainer == this.endContainer && this.startOffset == this.endOffset ) ;
    },

    // W3C requires a check for the new position. If it is after the end
    // boundary, the range should be collapsed to the new start. It seams we
    // will not need this check for our use of this class so we can ignore it for now.
    setStart : function( refNode, offset )
    {
        this.startContainer    = refNode ;
        this.startOffset    = offset ;

        if ( !this.endContainer )
        {
            this.endContainer    = refNode ;
            this.endOffset        = offset ;
        }

        this._UpdateCollapsed() ;
    },

    // W3C requires a check for the new position. If it is before the start
    // boundary, the range should be collapsed to the new end. It seams we
    // will not need this check for our use of this class so we can ignore it for now.
    setEnd : function( refNode, offset )
    {
        this.endContainer    = refNode ;
        this.endOffset        = offset ;

        if ( !this.startContainer )
        {
            this.startContainer    = refNode ;
            this.startOffset    = offset ;
        }

        this._UpdateCollapsed() ;
    },

    setStartAfter : function( refNode )
    {
        this.setStart( refNode.parentNode, FCKDomTools.GetIndexOf( refNode ) + 1 ) ;
    },

    setStartBefore : function( refNode )
    {
        this.setStart( refNode.parentNode, FCKDomTools.GetIndexOf( refNode ) ) ;
    },

    setEndAfter : function( refNode )
    {
        this.setEnd( refNode.parentNode, FCKDomTools.GetIndexOf( refNode ) + 1 ) ;
    },

    setEndBefore : function( refNode )
    {
        this.setEnd( refNode.parentNode, FCKDomTools.GetIndexOf( refNode ) ) ;
    },

    collapse : function( toStart )
    {
        if ( toStart )
        {
            this.endContainer    = this.startContainer ;
            this.endOffset        = this.startOffset ;
        }
        else
        {
            this.startContainer    = this.endContainer ;
            this.startOffset    = this.endOffset ;
        }

        this.collapsed = true ;
    },

    selectNodeContents : function( refNode )
    {
        this.setStart( refNode, 0 ) ;
        this.setEnd( refNode, refNode.nodeType == 3 ? refNode.data.length : refNode.childNodes.length ) ;
    },

    insertNode : function( newNode )
    {
        var startContainer = this.startContainer ;
        var startOffset = this.startOffset ;

        // If we are in a text node.
        if ( startContainer.nodeType == 3 )
        {
            startContainer.splitText( startOffset ) ;

            // Check if it is necessary to update the end boundary.
            if ( startContainer == this.endContainer )
                this.setEnd( startContainer.nextSibling, this.endOffset - this.startOffset ) ;

            // Insert the new node it after the text node.
            FCKDomTools.InsertAfterNode( startContainer, newNode ) ;

            return ;
        }
        else
        {
            // Simply insert the new node before the current start node.
            startContainer.insertBefore( newNode, startContainer.childNodes[ startOffset ] || null ) ;

            // Check if it is necessary to update the end boundary.
            if ( startContainer == this.endContainer )
            {
                this.endOffset++ ;
                this.collapsed = false ;
            }
        }
    },

    deleteContents : function()
    {
        if ( this.collapsed )
            return ;

        this._ExecContentsAction( 0 ) ;
    },

    extractContents : function()
    {
        var docFrag = new FCKDocumentFragment( this._Document ) ;

        if ( !this.collapsed )
            this._ExecContentsAction( 1, docFrag ) ;

        return docFrag ;
    },

    // The selection may be lost when cloning (due to the splitText() call).
    cloneContents : function()
    {
        var docFrag = new FCKDocumentFragment( this._Document ) ;

        if ( !this.collapsed )
            this._ExecContentsAction( 2, docFrag ) ;

        return docFrag ;
    },

    _ExecContentsAction : function( action, docFrag )
    {
        var startNode    = this.startContainer ;
        var endNode        = this.endContainer ;

        var startOffset    = this.startOffset ;
        var endOffset    = this.endOffset ;

        var removeStartNode    = false ;
        var removeEndNode    = false ;

        // Check the start and end nodes and make the necessary removals or changes.

        // Start from the end, otherwise DOM mutations (splitText) made in the
        // start boundary may interfere on the results here.

        // For text containers, we must simply split the node and point to the
        // second part. The removal will be handled by the rest of the code .
        if ( endNode.nodeType == 3 )
            endNode = endNode.splitText( endOffset ) ;
        else
        {
            // If the end container has children and the offset is pointing
            // to a child, then we should start from it.
            if ( endNode.childNodes.length > 0 )
            {
                // If the offset points after the last node.
                if ( endOffset > endNode.childNodes.length - 1 )
                {
                    // Let's create a temporary node and mark it for removal.
                    endNode = FCKDomTools.InsertAfterNode( endNode.lastChild, this._Document.createTextNode('') ) ;
                    removeEndNode = true ;
                }
                else
                    endNode = endNode.childNodes[ endOffset ] ;
            }
        }

        // For text containers, we must simply split the node. The removal will
        // be handled by the rest of the code .
        if ( startNode.nodeType == 3 )
        {
            startNode.splitText( startOffset ) ;

            // In cases the end node is the same as the start node, the above
            // splitting will also split the end, so me must move the end to
            // the second part of the split.
            if ( startNode == endNode )
                endNode = startNode.nextSibling ;
        }
        else
        {
            // If the start container has children and the offset is pointing
            // to a child, then we should start from its previous sibling.

            // If the offset points to the first node, we don't have a
            // sibling, so let's use the first one, but mark it for removal.
            if ( startOffset == 0 )
            {
                // Let's create a temporary node and mark it for removal.
                startNode = startNode.insertBefore( this._Document.createTextNode(''), startNode.firstChild ) ;
                removeStartNode = true ;
            }
            else if ( startOffset > startNode.childNodes.length - 1 )
            {
                // Let's create a temporary node and mark it for removal.
                startNode = startNode.appendChild( this._Document.createTextNode('') ) ;
                removeStartNode = true ;
            }
            else
                startNode = startNode.childNodes[ startOffset ].previousSibling ;
        }

        // Get the parent nodes tree for the start and end boundaries.
        var startParents    = FCKDomTools.GetParents( startNode ) ;
        var endParents        = FCKDomTools.GetParents( endNode ) ;

        // Compare them, to find the top most siblings.
        var i, topStart, topEnd ;

        for ( i = 0 ; i < startParents.length ; i++ )
        {
            topStart    = startParents[i] ;
            topEnd        = endParents[i] ;

            // The compared nodes will match until we find the top most
            // siblings (different nodes that have the same parent).
            // "i" will hold the index in the parents array for the top
            // most element.
            if ( topStart != topEnd )
                break ;
        }

        var clone, levelStartNode, levelClone, currentNode, currentSibling ;

        if ( docFrag )
            clone = docFrag.RootNode ;

        // Remove all successive sibling nodes for every node in the
        // startParents tree.
        for ( var j = i ; j < startParents.length ; j++ )
        {
            levelStartNode = startParents[j] ;

            // For Extract and Clone, we must clone this level.
            if ( clone && levelStartNode != startNode )        // action = 0 = Delete
                levelClone = clone.appendChild( levelStartNode.cloneNode( levelStartNode == startNode ) ) ;

            currentNode = levelStartNode.nextSibling ;

            while( currentNode )
            {
                // Stop processing when the current node matches a node in the
                // endParents tree or if it is the endNode.
                if ( currentNode == endParents[j] || currentNode == endNode )
                    break ;

                // Cache the next sibling.
                currentSibling = currentNode.nextSibling ;

                // If cloning, just clone it.
                if ( action == 2 )    // 2 = Clone
                    clone.appendChild( currentNode.cloneNode( true ) ) ;
                else
                {
                    // Both Delete and Extract will remove the node.
                    currentNode.parentNode.removeChild( currentNode ) ;

                    // When Extracting, move the removed node to the docFrag.
                    if ( action == 1 )    // 1 = Extract
                        clone.appendChild( currentNode ) ;
                }

                currentNode = currentSibling ;
            }

            if ( clone )
                clone = levelClone ;
        }

        if ( docFrag )
            clone = docFrag.RootNode ;

        // Remove all previous sibling nodes for every node in the
        // endParents tree.
        for ( var k = i ; k < endParents.length ; k++ )
        {
            levelStartNode = endParents[k] ;

            // For Extract and Clone, we must clone this level.
            if ( action > 0 && levelStartNode != endNode )        // action = 0 = Delete
                levelClone = clone.appendChild( levelStartNode.cloneNode( levelStartNode == endNode ) ) ;

            // The processing of siblings may have already been done by the parent.
            if ( !startParents[k] || levelStartNode.parentNode != startParents[k].parentNode )
            {
                currentNode = levelStartNode.previousSibling ;

                while( currentNode )
                {
                    // Stop processing when the current node matches a node in the
                    // startParents tree or if it is the startNode.
                    if ( currentNode == startParents[k] || currentNode == startNode )
                        break ;

                    // Cache the next sibling.
                    currentSibling = currentNode.previousSibling ;

                    // If cloning, just clone it.
                    if ( action == 2 )    // 2 = Clone
                        clone.insertBefore( currentNode.cloneNode( true ), clone.firstChild ) ;
                    else
                    {
                        // Both Delete and Extract will remove the node.
                        currentNode.parentNode.removeChild( currentNode ) ;

                        // When Extracting, mode the removed node to the docFrag.
                        if ( action == 1 )    // 1 = Extract
                            clone.insertBefore( currentNode, clone.firstChild ) ;
                    }

                    currentNode = currentSibling ;
                }
            }

            if ( clone )
                clone = levelClone ;
        }

        if ( action == 2 )        // 2 = Clone.
        {
            // No changes in the DOM should be done, so fix the split text (if any).

            var startTextNode = this.startContainer ;
            if ( startTextNode.nodeType == 3 )
            {
                startTextNode.data += startTextNode.nextSibling.data ;
                startTextNode.parentNode.removeChild( startTextNode.nextSibling ) ;
            }

            var endTextNode = this.endContainer ;
            if ( endTextNode.nodeType == 3 && endTextNode.nextSibling )
            {
                endTextNode.data += endTextNode.nextSibling.data ;
                endTextNode.parentNode.removeChild( endTextNode.nextSibling ) ;
            }
        }
        else
        {
            // Collapse the range.

            // If a node has been partially selected, collapse the range between
            // topStart and topEnd. Otherwise, simply collapse it to the start. (W3C specs).
            if ( topStart && topEnd && ( startNode.parentNode != topStart.parentNode || endNode.parentNode != topEnd.parentNode ) )
            {
                var endIndex = FCKDomTools.GetIndexOf( topEnd ) ;

                // If the start node is to be removed, we must correct the
                // index to reflect the removal.
                if ( removeStartNode && topEnd.parentNode == startNode.parentNode )
                    endIndex-- ;

                this.setStart( topEnd.parentNode, endIndex ) ;
            }

            // Collapse it to the start.
            this.collapse( true ) ;
        }

        // Cleanup any marked node.
        if( removeStartNode )
            startNode.parentNode.removeChild( startNode ) ;

        if( removeEndNode && endNode.parentNode )
            endNode.parentNode.removeChild( endNode ) ;
    },

    cloneRange : function()
    {
        return FCKW3CRange.CreateFromRange( this._Document, this ) ;
    }
} ;
